Quantitative Mass Spectrometry incorporates collaborative projects in which the Mass Spectrometry Group provides quantitative information about, typically, small molecules by GCMS, LCMS and LCMSMS or a combination. An example of the types of projects this includes is the isoprostane analyses undertaken as part of the NIEHS led study of biomarkers of oxidative stress. We currently have several major collaborations underway. 1) with the Zeldin Lab quantitating arachidonic acid metabolites that are relevant to inflammatory, vasodilatory, endothelial protective and post-ischemic cardioprotective effects. We ahve also provided quantiative information relevant to research identifying the role of epoxyeicosatrienoic acids in the control of angiogenesis-dependent regeneration, cancer, and metastasis. 2) Investigating the relationship between levels of EETs and DHETs and blood pressure, and levels of prostaglandin E2 and pulmonary fibrosis 3) Quantitate Bisphenol A exposure from rodent bedding and diet to help assess the importance given to the estrogenic content of the animal's diet, bedding, caging, and water bottles when evaluating the estrogenic activity of bisphenol A. 4) Identify lipid/s carried by the dust mite antigen Blag1 in collaboration with G. Mueller (LSB) and Lars Pedersen (LSB) 5) Quantitate cholestenoic acid in serum as a potential marker ofseverity and length of recovery of chronic lung disease